Apparatus for making dental fillings, bridges, and the like.



I D. s. MACKENZIE. APPARATUS FOR MAKING DENTAL FILLINGS, BRIDGES, ANDTHE LIKE.

APPLICATION FILED JUNE 7, 1910. 1,048,982.

Patented Dec. 31, 1912.

DAVID STUART MACKENZIE, 0F LEVIN. NE'VV ZEALANI APPARATUS FOR MAKINGDENTAL FILLINGSQ, BRIDGES, AND THE LIKE.

Application filed June 7, 1916.

To all whom it may concern:

Be it known that I, Du'tn STUART MAC- KENZIE, a citizen of the Dominionof New Zenhmd, and residing at Levin, in the Provincial District of\Vellington, in the Dominion of New Zealand, have invented certein newand useful Improvements in Appzi ratns for Mnkin Dental Fillings,Bridges, and the Like, 0 which the following is n specification.

This invention relates to improvements in apparatus for casting dentalfillings, crowns, plates, bridges and the like and the object of theinvention is to provide means whereby the flow of metal into the moldsis assisted by pressure above and a vacuum below the mold.

In the accompanying drawings, l ignre l is a. side elevation of anapparatus constructed in accordance with the invention; Fig. 2 is a planview; Fig. 3 is a vertical sectional view on the line B-B of Fig. 2;Fig. 4 is a detail view.

The particular embodiment of the invention illustrated is adapted foruse in ,lnrge business and the several parts are of such size that the a)paratus is not readily portable. It will e understood however thatthere can be variation in this particular without departing from theinvention.

Referring to the drawings, 30 designates a vacuum pump which isconnected with a reservoir 31 by means including a stop cool; 32. Thereservoir is provided with an ordinnry vacuum gage 33 and communicatesthrough a pipe 3% having therein it stop valve (Set with the lower endof n cup-like container 35 shown as having a stepped bottom, whereby itadapted to receive cyl inders 37 of various sizes, the cylinders andproper portion of the container bottom lacing connected by sorewthreads. Said cylinders may be connected with the cup by suitablethreads so that a cylinder of proper size for the pi rticnlnr Work to beperformed may be readily fitted in place.

\Vithin the cylinder is arranged the usual investment material in whichthe mold formed. said mold conunnnirnting with a rent: G at the upperend of the cylinder adapted to receive the moduli-ti be melted. Ainntlle 40 of tire chi reinforced with continuous wires 39 havingterminals 41, 4 :2. surrounds the cylinder 37 and a washer 35 ofasbestos is preferably arranged between said lnuille and the cup Thecylinder and Specification of Letters Yatent.

Patented Dec. 31, 1912.

Serial No. 565,625.

motile are inclosed in a casing 49 and a body of asbestos it? throughwhich the terminals of the wires of the motile extend, a metal cover 50being provided, far the upper end of sueh (using which is supported by ahose plate The cover is providcdwith a removable lid 51 for on opening,through which adapted to pass; n cover 59 for the cylinder 3?, saidcylindercovor havin in its inner surface an zibsorlnznt pad preFernbIymade of asbestos. Solid, cylinder cover is carried by a rod or stem 55Slidtlbly su ported in a bracket 56 which. is pivotaliy connected at 437to 3 cross bur 5 supported by uprights or standards .53 that rise fromthe bin. At its zipper or outer end said rod 555 has a heno or crossbar58 by means of whieh the rod and cylinder cover 55) may he moved tofinil from position to cause the cover to fit upon the upper end of thecylintler 37'.

When

t device is in use. the bracket 56 is secured against movement about itspivot 57 hymen-us of n holtiil engaging n slot 2 supporting nieniher Byloosening such bolt nno adios-ting the rod 55 vertically to car: the or;er 5?) above the top of the easing 45 the bracket can be turned upon itspivot-so that contents of the muilie may be exposed. and readilyexamined. The

wires 39 form part of ii.

v:ircuit including an electriegenerator H and n rheostat 45 isintroduced into one branch 46 of such circnit. p

in. using; the apparatus it suitable mold is prepared and arrangedwithin the cylinder 37 secured to the cup as before described, and bymenus of an electric current the mnille is suitably heated While the lidM of the ending 19 is in plane and the cover 59 for the cylinder 37 isin the p sition shown in Fig. 1. Vv 'hcn the temperature within thecasing 49 has been raised sntliricntly high to melt the metal in therecess 6, the lid 51 of the casin is removed and the bracket 56 and stem3:3 adjusted as to position the rover 71! upon the cylinder, 37, the pad(30 within such cover having been suitably loosened. \Vithin the stopcork (H in the pipe ill is opened to establish ronnnunicm tion betweenthe cup 35 and the vacuum resorroir iii. The steam generated by thoEhllflll of the heat of the (using upon the mixture (Dillilllltii in thepaid (it) oi the, rover 55) of the mold cylinder and the vacuum net toforce the n'ictnl into the mold.

Having described my invention what is claimed and desired to be securedby Letters-Patent is, i

1. The combination, in an apparatus of the character described, of avertically arcasing, and means supporting said closure and adapting itto be moved vertically to and from the mold casing and to rock about ahorizontal axis. a

2. Apparatus of the kind described, comprising the combination of acylinder and mold contained therein, with a cu fitting the end of thecylinder, an electric muifie surrounding the cylinder, means forgenerating an electric current in the mufiie, a casing having aremovable lid and containing the mufile, asbestos material surroundingthe mufile, a cover adapted to pass into the ms in and close the top ofthe cylinder, and an as estos pad within the cover, substantially as setforth.

3. Apparatus of the kind described, comprising the combination of acylinder, and mold contained therein, with a cup fitting the end of thecylinder, a base plate su porting the cup, an electric muflie surrouning the cylinder, means for generatin an electric current in the mufile,a casing aving a removable lid and containing the mufile, a standardrising from the base plate and having horizontal arms, a rod slidable inthe arms, a cover fixed to the rod and adapted to fit upon the cylinder,substantially as set-forth.

In'testimony whereof I have aflixed my signaturein'presence of twowitnesses.

DAVID STUART MACKENZIE.

Witnesses:

ERNEST SMITH BALDWIN, ANNIE DOROTHY MCKENZIE.

